The present invention relates generally to cleaning of boiler interiors, and more particularly to a novel system for cleaning boilers which finds particular application in de-scaling boilers of apparatus having boilers that are difficult or inconvenient to access.
A major problem with any device which heats or boils water is scale buildup in the boiler. Dissolved solids in the water precipitate and bond to surfaces in contact with the water. This scale can build up to levels which cause blockage of drains, damage valves, cause heater failure in electric boilers, and greatly reduce efficiency in gas-fired units.
One technique to reduce scale buildup in boilers is to employ a water conditioner which removes solids from the water being introduced into the boiler. However, such water conditioners are relatively expensive and require regular maintenance. A more common practice is to periodically de-scale the boilers. This is generally done by introducing a strong acid, such as phosphoric acid, into the boiler. The acid is allowed to stand and dissolve the scale, after which the boiler is flushed and drained to remove the acid and dissolved scale. This technique has been found quite satisfactory but presents a significant safety problem when introducing the acid into the boiler.
The safety problems inherent in introducing acid descaling solutions into boilers are particularly acute when cleaning gas-fired boilers or combination steam and dry air cooking ovens and the like wherein the boilers are housed within the oven cabinets rearwardly of associated cooking compartments. Such boilers are commonly accessed from the top rear of the oven cabinet generally through a pressure relief port or fill port at the top of the boiler. This often makes it necessary to climb on top of the cabinet which may be hot from use, slippery from cooking grease, or located close to other equipment. Moreover, since such access is carried out while holding strong acids, the safety problems are magnified. Also, since commercial oven units are often double stacked, additional problems are presented by the height of the access port in the upper boiler, and the increased difficulty in reaching the access port in the lower boiler. In addition to overcoming safety problems, boiler cleaning systems should be simple in operation and not require service calls or the use of specialized tools.